sump or not to sump?

This is a discussion on sump or not to sump? within the Freshwater Aquarium Equipment forums, part of the Beginner Freshwater Aquarium category; -->
Hi peeps
I was looking around the net for aquarium supplies, as i'm quite new to all this and i was wondering what a ...

Hi peeps
I was looking around the net for aquarium supplies, as i'm quite new to all this and i was wondering what a sump is for? Is to to enable you to stock more fish? or just to make changing water easier?
If it enables you to stock more fish then i'm interested as i have a space under my aquarium made for this i think :)

Many thanks for your responses, that has cleared things up for me :)
I should have realised it was to hide the filter and other ugly bits out of the way. ha ha silly me, and there i was thinking that if i had a 10g sump with a 30g tank it would in effect let the stocking level be equal to a 40g setup